ISP connectivity VLAN ID settings?

[petarshsr]

Hello, I'm using ASUS router at home and I had some network connectivity issues so the technical support had to come and check it.

The router interface uses dynamic IP addresses. 

The technician came and opened the LAN -> IPTV section of the router, entered "Manual Settings" under Lan Port tab, and some VID under the Internet tab.

However right now I cannot seem to configure my lab Cisco router (Cisco 871). 

I can configure it with static IP address, but the WAN interface cannot receive IP address after I enter "ip address dhcp" and clone the MAC address from the ASUS router which has internet connectivity. 

Where should I enter the VLAN command the technician entered in the ASUS router? Only with that tag I can receive IP address, but I cannot seem to figure out where to enter in in the Cisco router. I was thinking about subinterface, but I don't know if I'm on the right track.

[Giuseppe Larosa]

Hello @petarshsr ,

yes you need to use a subinterface where you can use a command like

encapsulation dot1q <vlan-id>

move the command to get an IP address from DHCP under the subinterface as well.

However, be aware that your ISP might be using PPPoE in that case the configuration of the subinterface would be quite different.

Edit:

I see the mention of IPTV  take in account that some ISPs use actually two VLAN-IDs like two subinterfaces one for internet access and one for IPTV service. ( this is done for QoS Quality of Service reasons)

Hope to help

Giuseppe